[A case of idiopathic pulmonary fibrosis with histology of usual interstitial pneumonia that responded to pulse therapy followed by combined immunosuppression with prednisolone and azathioprine].

A 64-year-old woman who was admitted with cough and dyspnea showed severe hypoxemia and interstitial lung shadows. The clinical diagnosis was idiopathic interstitial pneumonia (synonymous with idiopathic pulmonary fibrosis in the United States), since there were no specific immunological or bacteriological findings. No clinical signs or laboratory data compatible with collagen disease were observed. Methylprednisolone pulse therapy was given followed by prednisolone (0.8 mg/kg) and azathioprine (15 mg/kg). Marked improvement of hypoxia, chest X-ray and spirometry results was observed after five weeks. Histological examination of an cases of residual interstitial shadow obtained by open lung biopsy revealed usual interstitial pneumonia. Tapering of the immunosuppressant drugs led to a recurrence 3 months later, which was controlled by reintroduction of the same regimen. Therefore, only prednisolone was tapered, and data obtained in an outpatient clinic 6 months after the recurrence were as follows: %VC 108%, %DLco 72%, PaO2 80 Torr. The value of this regimen for acute IPF or exacerbation of IPF is suggested because of its life-saving effects.